Keep your items safe and dry while paddling.  these are a great addition to your board, and are extremely handy to have.  We never go paddling without ours - in fact mine stays in my car 24/7! This is a 20 liter bag, which we feel is the perfect size - not too bulky yet not too small. Keep a little bit of air in the bag so it floats if it falls off. Comes with a removable shoulder strap. Made with heavy duty, vinyl-coated fabric for watertight protection.